139209840 has 560 divisors, whose sum is σ = 624531456. Its totient is φ = 27993600.

The previous prime is 139209839. The next prime is 139209857. The reversal of 139209840 is 48902931.

It is a tau number, because it is divible by the number of its divisors (560).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 139209795 and 139209804.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 4490625 + ... + 4490655.

Almost surely, 2^139209840 is an apocalyptic number.

139209840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 139209840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (312265728).

139209840 is an abundant number, since it is smaller than the sum of its proper divisors (485321616).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

139209840 is a wasteful number, since it uses less digits than its factorization.

139209840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80 (or 59 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 139209840 is about 11798.7219646875. The cubic root of 139209840 is about 518.2706853378.

The spelling of 139209840 in words is "one hundred thirty-nine million, two hundred nine thousand, eight hundred forty".